Taxonomic Classification of some Members of the NEOs Atiras Population

To observe IEOs population, such as the NEOs Atiras, is a great challenge since they are only possible to observe at low altitudes with very short observational time window, close to evening and morning twilights which could cause images affected by the glare of the Sun. Therefore, the physical properties of these objects are poorly known. In this work we performed a taxonomic study of these objects, using an analysis of phase curve, colors and spectra, where the classification through these different techniques is consistent. Using the phase curve and colors we obtained a preliminary taxonomic classification for the NEOs-Atiras (163693) Atira and (481817) 2008 UL90, both associated to low-albedo classes, P or C. The classification of (413563) 2005 TG45, on the other hand, is related to a silicate-rich class such as S, Q, V, R or A-type. Using photometric spectra we found that 2021 PH27 is a B-type. Furthermore, using spectroscopy we found that 2008 EA32 is an L-type and 2017 YH is an O-type or Q-type. However, considering that 2008 EA32 could have been affected by phase reddening and space weathering, it is possible that their classification changed from Q- or S- to L-type. In contrast, despite the proximity of the Sun and a large observational phase angle, asteroid 2017 YH maintains a moderate spectral slope. This suggest an extremely young surface that may have recently undergone a resurfacing process. In general, these results indicate diverse possible origins for the NEOs-Atiras population.